Edward John Zacharski

US Patent:

40192016, Apr 19, 1977

Filed:

Sep 2, 1975

Appl. No.:

5/609573

Inventors:

Albert F. Hartung - Woodland Hills CA
Frank W. Lehan - Santa Barbara CA
Charles T. Barooshian - Pacific Palisades CA
Edward J. Zacharski - Malibu CA

Assignee:

System Development Corporation - Santa Monica CA

International Classification:

H04N 144

US Classification:

358124

Abstract:

Method and apparatus for scrambling and unscrambling television video and audio signals in a subscription television system in which program selections of subscribers are known at a central transmitting site, and control signals encoded into vertical blanking intervals of the video signals are addressed to receivers authorized to receive unscrambled transmissions, to selectively control unscrambling at those receivers. In an unscrambler at each subscriber's receiver, the control signals are decoded, and, if addressed to the particular subscriber's receiver, operate to enable or disable the unscrambler, or to frequently vary its mode of operation, thereby greatly increasing the security of the system and deterring viewing of scrambled transmissions. Video scrambling and unscrambling are effected by inversion of selected horizontal lines of a transmitted television picture, and a technique is disclosed for inversion or non-inversion selected on a line-by-line basis, with an appropriate control signal being transmitted with each line.

US Patent:

40458148, Aug 30, 1977

Filed:

Sep 2, 1975

Appl. No.:

5/609572

Inventors:

Albert F. Hartung - Woodland Hills CA
Frank W. Lehan - Santa Barbara CA
Charles T. Barooshian - Pacific Palisades CA
Edward J. Zacharski - Malibu CA

Assignee:

System Development Corporation - Santa Monica CA

International Classification:

H04N 144

US Classification:

358124

Abstract:

Method and apparatus for scrambling and unscrambling television video and audio signals in a subscription television system in which program selections of subscribers are known at a central transmitting site, and control signals encoded into vertical blanking intervals of the video signals are addressed to receivers authorized to receive unscrambled transmissions, to selectively control unscrambling at those receivers. In an unscrambler at each subscriber's receiver, the control signals are decoded, and, if addressed to the particular subscriber's receiver, operate to enable or disable the unscrambler, or to frequently vary its mode of operation, thereby greatly increasing the security of the system and deterring viewing of scrambled transmissions. Video scrambling and unscrambling are effected by inversion of selected horizontal lines of a transmitted television picture, and a technique is disclosed for inversion of alternate groups of equal numbers of line.

US Patent:

40245764, May 17, 1977

Filed:

Sep 2, 1975

Appl. No.:

5/609577

Inventors:

Albert F. Hartung - Woodland Hills CA
Frank W. Lehan - Santa Barbara CA
Charles T. Barooshian - Pacific Palisades CA
Edward J. Zacharski - Malibu CA

Assignee:

System Development Corporation - Santa Monica CA

International Classification:

H04N 144

US Classification:

358124

Abstract:

Method and apparatus for scrambling and unscrambling television video and audio signals in a subscription television system in which program selections of subscribers are known at a central transmitting site, and control signals encoded into vertical blanking intervals of the video signals are addressed to receivers authorized to receive unscrambled transmissions, to selectively control unscrambling at those receivers. In an unscrambler at each subscriber's receiver, the control signals are decoded, and, if addressed to the particular subscriber's receiver, operate to enable or disable the unscrambler, or to frequently vary its mode of operation, thereby greatly increasing the security of the system and deterring viewing of scrambled transmissions. Video scrambling and unscrambling are effected by inversion of selected horizontal lines of a transmitted television picture, and a technique is disclosed for inversion or non-inversion in a preselected sequence, as determined by synchronized logic at the receivers and the transmitting site.